Composite Sodium Cathode Material With Dual Coating for Cycle Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sodium ion batteries face challenges with cycle life, rate performance, and cost due to unstable structure and low capacity, limiting their application in large-scale energy storage technologies.
Innovation Solution
A sodium battery cathode electrode material with a chemical formula of xNaMBO3·yNa2Ti3O7·zNa3V2(BO3)3/C, where x:y:z is 0.94-0.96:0.02-0.03, M is Fe and Mn, and the mass fraction of carbon is 1.2-1.5%, coated with Na2Ti3O7 and Na3V2(BO3)3, and an amorphous carbon layer, is developed, along with a specific preparation method involving multiple calcination steps and surface coating to enhance stability and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional sodium battery materials are used, then cost is reduced, but cycle life and rate performance deteriorate
Solution Approach 1:
The patent employs a composite cathode material consisting of NaMBO3 core particles coated with Na2Ti3O7 and Na3V2(BO3)3 layers. This composite structure combines the low cost of NaMBO3 with the superior stability of the coating materials, achieving both cost reduction and improved cycle life. The coating layers protect the core material from degradation while maintaining electrochemical performance.
Solution Approach 2:
The patent applies surface coating technology where Na2Ti3O7 and Na3V2(BO3)3 are deposited on the surface of NaMBO3 particles. This local modification approach maintains the bulk properties of the low-cost NaMBO3 material while improving surface stability and resistance to degradation, thereby enhancing cycle life without significantly increasing cost.
2Ease of manufacture
If conventional sodium battery materials are used, then cost is reduced, but capacity deteriorates
Solution Approach 1:
The composite structure of NaMBO3 core with Na2Ti3O7 and Na3V2(BO3)3 coating enables the material to achieve higher capacity than conventional sodium battery materials. The coating layers facilitate better ion transport and structural stability, allowing the low-cost NaMBO3 core to deliver enhanced capacity performance.
3Quantity of substance
If sodium ion batteries are developed, then resource availability is improved, but structure stability deteriorates
Solution Approach 1:
The patent uses surface coating to locally modify the structure of NaMBO3 particles. The Na2Ti3O7 and Na3V2(BO3)3 coating layers are applied specifically on the surface where structural degradation occurs during cycling, providing localized stability enhancement without altering the bulk composition and maintaining resource availability advantages.
Solution Approach 2:
The composite material design combines the resource-abundant NaMBO3 with structurally stable coating materials. This composite approach leverages the advantages of both components: the low cost and resource availability of sodium-based materials and the structural stability of the coating layers, achieving improved structure stability overall.
4Quantity of substance
If sodium ion batteries are developed, then resource availability is improved, but resistance to oxidation and moisture deteriorates
Solution Approach 1:
The patent applies protective coating layers on the surface of NaMBO3 particles to locally enhance resistance to oxidation and moisture. The coating materials Na2Ti3O7 and Na3V2(BO3)3 form a protective barrier that prevents direct contact between the core material and harmful environmental factors, while the bulk material maintains its resource availability advantages.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The material exhibits high capacity, stable structure, and improved cycle performance, while being cost-effective due to the use of borate and lower-cost manganese and iron, with enhanced oxidation and moisture resistance, and improved ion and electronic conductivity.
Implementation Method 1
the first coating layer includes Na2Ti3O7 and Na3V2(BO3)3
Implementation Method 2
the second coating layer is amorphous carbon
Implementation Method 3
the specific phase transition process, storage mechanism, and interface process of its intercalation and de-intercalation in electrode materials
Data Source
AI summary
The present disclosure provides a sodium battery cathode electrode material, which has a chemical formula as follows: xNaMBO3·yNa2Ti3O7·zNa3V2(BO3)3/C, wherein the mole number ratio of x to y to z is 0.94-0.96:0.02-0.03:0.02-0.03; M is Fe and Mn, and the mole number ratio of Fe to Mn is 8-9:1-2; and the mass fraction of carbon in the sodium battery cathode electrode material is 1.2% to 1.5%. The sodium battery cathode electrode material provided by the present disclosure is high in capacity, high in voltage platform, stable in structure and high in cycle performance, and the preparation method is simple, low in cost and short in process flow.